Process for the manufacture of oximino-dithiolanes

ABSTRACT

The invention provides a new cyclization reaction to obtain 4alkenyl-2-oximino-1,3-dithiolanes by reacting a trans-or cis-1,4dihalogeno-2-butene with a salt of a dithiocarbamic acid and further reacting the resulting intermediate product 4-alkenyl-2imino-1,3-dithiolane in the usual way with hydroxylamine.

United States Patent Nikles July 18, 1972 [54] PROCESS FOR THE MANUFACTURE [56] References Cited 0F OXIMINO-DITHIOLANES UNITED STATES PATENTS Inventor: Erwin Nikles, Liestal Switzerland 3,484,455 12/1969 Addor ..260/327 [73] Assignee: Ciba-Gelgy AG, Basel, Switzerland Primary Examiner-Henry R. Jiles Assistant ExaminerCecilia M. Shurko [221 1970 Attorney-Harry Goldsmith, Joseph G. Kolodny and Mario A. [211 App]. No.: 13,764 Monaco [57] ABSTRACT [30] reign Application Horny Dam The invention provides a new cyclization reaction to obtain 4- Feb. 27, 1969 Switzerland ..2966/69 alkenyl-2-0Ximin0-Lidithiolanes y reacting a trans-0r 1,4-dihalogeno-2-butene with a salt of a dithiocarbamic acid 7 and further reacting the resulting intermediate product 4-alke- [52] US. Cl ..260/327 M, 71/90, 424/277 nyl-2-imjno-l,3-dithiolane in the usual way with hydrox- [51] Int. Cl. .C07d 71/00 ylamine. [58] 8Claims,No Drawings Held of Search ..260/327 M PROCESS FOR THE MANUFACTURE OF OXIMINO- DITHIOLANES The present invention provides a process for the manufacture of 4-alkenyl-2-oximino-1,3-dithiolanes of the general formula lit JIM- C R2 NOH p in which R, and R each represents a hydrogen atom or an alkyl group, preferably a lower alkyl group, R and R being the same or different, wherein a trans or cis-l,4-dihalogeno-2- butene of the general formula in which Hal represents a halogen atom, is cyclized with a salt of a dithiocarbamic acid of the general formula mula t l s R?[ NR' A. S

CHF

which is reacted with hydroxylamine to form the oxime thereof.

Preferably R represents a lower alkyl group. The term Hal refers especially to a chlorine or a bromine atom, preferably a chlorine atom. The term lower alkyl group refers to CH C H n-C H iso-C H,, n-C,,H and iso-C H The reaction temperatures may be varied within a very wide range. The preferred range is from to 100 C. The reaction may be carried out in the presence of a diluent.

The process of the invention is advantageous in that the starting material is easily obtainable and high yields are obtained in a clear, straightforward reaction.

Since the compounds can also be cyclized in a manner known per se using a l,2-dihalogeno-3-butene as starting material, a high degree of technical efficiency is possible in that, for example, technical dichlorobutene mixtures obtained by the chlorination of butadiene can be used directly for the cyclization process and the desired compound is obtained as the sole end-product.

The compounds of Formula I and the derivatives thereof may be used for a wide variety of purposes; for example, they may be used in the processing of rubber, as intermediate products in the synthesis of medicaments and as intermediate products for obtaining pesticidal dithiolanyl-oximinocarbamates by reacting them with alkylisocyanates. 1,3-Dithiolanyloximinocarbamates of the general formula ll Ila are obtained by reacting the oximino-dithiolane compounds of formula I with an isocyanate R -NCO, in which R represents hydrogen or a lower alkyl group and R represents hydrogen, or by reacting the oximino-dithiolane compounds of formula I with a carbamic acid halide of the formula hal--CON(R )(R,) in which R represents hydrogen or a methyl group and R, represents a lower alkyl group. ln the compound of the general formula ll, R and R each represents a hydrogen atom or a lower alkyl group. The term lower alkyl group" as used here is a CH C H n-C H- iso-C H,, n-C,H secondary C.,H iso-C H tertiary C,H n-C H iso-C H or secondary C H group.

The compounds of formula II have a surprising range of biological activity as is observed either in the far-reaching control of pests or when used in the form of herbicides in areas of cultivated plants where they have a favorable effecton the useful plants.

As carriers there may be used, for example, solvents, diluents, dispersants, emulsifiers, wetting agents, adhesives, binders or thickening agents.

The compounds of the formula ll also act as molluscicides, especially against gastropodes which are schistosome carriers. Furthermore, when applied in very small amounts the new compounds display a good microbicidal activity against bacteria and fungi, especially against phytopathogenic fungi, for example, Erysiphe cichoracearum, Alternaria tenuis and solani. In the concentrations required for this use no damage to the plants can be detected.

Furthermore, the compounds of the formula ll act against nematodes, for example, Panagrellus redivivus, Meloidogne sp. and others, and have also a very good insecticidal and acaricidal activity which is distinguished biologically in a distinct manner by chemosterilizing properties.

Thus, for example, these carbamates act strongly against houseflies, aphids, caterpillars and beetles, for example, cornweevil and Colorado beetle. Their contact effect surpasses substantially that of the known active substance Carbaryl" (N-methyl-a-naphthyl-carbamate).

Their activity against Phyllodromia germanica, Periplaneta americana, Blatta orientalis, Acheta domestica and Rhodnius prolixus is especially strong.

The new carbamates are, therefore, very suitable for controlling pests in the hygiene sector and in protecting stored products.

Their activity against Diptera, Coleoptera, Rhynchoti and Lepidoptera makes them an especially suitable type of compound. Soil insects can be controlled in the soil with very small amounts.

It should be specially mentioned that known rice pests, for example, Nephotettix cincticeps, Nilaparvata lugens, Sogatella fureifera or the rice stem borer Chilo suppressalis, and cotton pests, for example, Prodenia or Anthonomus, can all be effectively controlled.

The toxicity of the compounds of the formula ll towards warm-blooded beings is 10 to 20 times lower than that of 1,3- dithiolanyl-oximino-N-methylcarbamate. They undergo decomposition in the soil and no residues remain in the cultivated soil for a long time.

The following Example illustrates the invention, the parts being by weight unless otherwise indicated.

EXAMPLE 2-lsopropylimino-4-vinyl-l ,3-dithiolane 194 Parts of isopropylammoniumisopropyldithiocarbamate are introduced at 30 to 35 C, while stirring, into a mixture comprising I65 parts of potassium carbonate, 125 parts of cisl,4-dichloro-2-butene and l,500 parts by volume of anhydrous alcohol. The suspension is then refluxed for 14 hours, cooled to room temperature and filtered. The filtrate is evaporated, taken up in parts by volume of a 1:1 mixture of benzene and cyclohexane, filtered and evaporated. The residue is distilled in a high vacuum. B.p. l06-l 12 C/0.025 mm Hg.

The same product is also obtained when the cis-l,4- dichloro-Z-butene is replaced by the corresponding transisomer. 2-Oximino-4-vinyll ,B-dithiolane 38.5 Parts of 2-isopropylimino-4-vinyl-l,3-dithiolane are mixed with 100 parts by volume of alcohol and then l6 parts of hydroxylamine hydrochloride, dissolved in 30 parts of water, are added. The mixture is refluxed for hours, poured on to 2,000 parts of ice-water and then dissolved in ether. The ethereal solution is extracted with an N-sodium hydroxide solution. The alkaline extract is rendered neutral with concentrated hydrochloric acid while cooling with ice, and then extracted with chloroform. The chloroform solution is dried over anhydrous sodium sulphate, filtered and evaporated. The product remains behind in the form of an oil.

NMR spectrum: S-values [(DClJT MS] m=3.03.8 (2H) (CH lclaim: l. A process for the manufacture of 4-alkenyl-2-oximino- 1,3-dithiolanes of the general formula wherein a trans or cis-l ,4-dihalogeno-2-butene of the general formula in which Hal represents a halogen atom, is cyclized with a salt of a dithiocarbamic acid of the general formula in which R represents a hydrogen atom or any aliphatic or aromatic radical bound by way of a carbon atom and X represents a monovalent cation, to obtain a compound of the general formula which is reacted with hydroxylamine to form the oxime thereof.

2. A process according to claim 1, wherein Hal" represents a chlorine atom.

3. A process according to claim 1, wherein trans or cis-l,4- dichloro-Z-butene is used.

4. A process according to claim 1, wherein R represents a lower alkyl group.

5. A process according to claim 1, wherein as salt of a dithiocarbamic acid, a compound of the general formula lntmisl l l in which R represents a hydrogen atom or a lower alkyl group, is used.

6. A process according to claim 1, wherein the reactions are carried out at a temperature of from 20 to C.

7. A process according to claim 1, wherein the reactions are carried out in the presence of a diluent.

8. The compound of the formula CI-IFCH S 

2. A process according to claim 1, wherein ''''Hal'''' represents a chlorine atom.
 3. A process according to claim 1, wherein trans or cis-1,4-dichloro-2-butene is used.
 4. A process according to claim 1, wherein R'' represents a lower alkyl group.
 5. A process according to claim 1, wherein as salt of a dithiocarbamic acid, a compound of the general formula in which R'' represents a hydrogen atom or a lower alkyl group, is used.
 6. A process according to claim 1, wherein the reactions are carried out at a temperature of from 20* to 100* C.
 7. A process according to claim 1, wherein the reactions are carried out in the presence of a diluent.
 8. The compound of the formula 